The Malicious House is a rare event where the player spawns in a medium sized house. The interior of the house is bathed in an insidious red glow.
In one of the rooms, the player encounters a mysterious looking obelisk and when interacted with gives the player a choice to either touch the obelisk or refuse. This results in the character interacting with the obelisk taking 2 hit points of damage (lethal) and gaining a point in strength, fitness or shooting.
If the obelisk kills a party member it will drop a weapon or supplies for the remaining party members. The effects of interacting with the obelisk can be replicated by switching between characters. The weapons are usually not very good.
The interior of the house will revert back to its original color once the player chooses to touch the obelisk. However, there is a visual glitch where if you enter a few rooms it will turn red again.